Touch Sensor System with Memory

ABSTRACT

A touch sensor system. The touch sensor system may include a touch sensor configured to provide an output in response to contact with a touch area, a controller coupled to the touch sensor and configured to provide a code representative of the output and a memory coupled to the controller. The memory may be configured to receive and store the code in a first time interval and to provide the code in a second time interval wherein the second time interval begins after the first time interval ends. Adjacent key suppression algorithms are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit 61/156,202 filed Feb. 27, 2009 and titled Touch Sensor System with Memory, which is fully incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to touch sensor systems with memory and methods.

BACKGROUND

A vehicle may include assemblies for controlling activation or deactivation of a device. The automotive industry has required that such devices provide tactile feedback to a user to indicate when a function has been activated or deactivated. Tactile feedback may be achieved using associated mechanical components, such as a spring and lever in an “over the center” snap-acting arrangement (e.g. in a rocker mechanism), or by the use of other known tactile feedback configurations.

These configurations typically require several components and features. Some of the components may be difficult and expensive to manufacture. For example, a pivot race and pivot shaft for a rocker button may have narrow tolerances and require a highly polished surface to reduce frictional forces. Conventional assemblies may thus involve complex design, high costs, and reduced reliability. In addition, consumer preferences are leading automobile manufacturers to more streamlined and unobtrusive systems.

At least in part to address these issues, touch sensor configurations have been adopted. As used herein the term “touch sensor” refers to a sensor configuration that provides an output in response to contact with a touch area without requiring movement of a mechanical component to electrically close or open associated contacts. Numerous analog and digital touch sensor configurations are well-known to those of ordinary skill in the art. Known touch sensors use techniques such as resistive sensing, capacitive sensing, acoustic sensing, magnetic sensing, optical sensing, etc., to providing an output in response to contact with a touch area.

Touch sensor configurations may be less expensive compared to conventional mechanical switch devices, may require less space for installation, and may be more aesthetically pleasing. Typically, however, touch sensor configurations have not provided tactile feedback. Also, in multiple sensor configurations cross-talk between adjacent touch sensors may prevent or delay proper system operation, and conventional touch sensor systems may be challenged by harsh environmental conditions, e.g. rain, ice, extreme temperature, vibration, etc.

In many applications, due to space limitations, a limited number of touch sensors may be accommodated. In such applications, it may be desirable to use one or more touch sensors for more than one function. In other words, a plurality of touch sensors may be configured to each provide an output when individually touched and to provide a different output when touched substantially in parallel. For example, in automotive applications, unlocking a door may include a plurality of individual touch sensor touches in a specified sequence. Locking a door may include touching a plurality of touch sensors substantially in parallel, i.e., touching a first touch sensor and touching a second touch sensor while continuing to touch the first touch sensor. It may then be desirable to configure a touch sensor system to accommodate multiple functions for the touch sensors.

In some applications, e.g., an automotive door unlock sequence, a user may touch a known unlock sequence relatively rapidly. It may be desirable to detect the sequence of relatively rapid touches, store a portion or all of the sequence and output the sequence at a rate appropriate for a receiving device. It may also be desirable to differentiate between a user intentionally and unintentionally touching multiple touch sensors substantially in parallel in order to provide an appropriate response. For example, it may be desirable to not lock a vehicle doors in response to a user unintentionally touching multiple touch sensors, e.g., during car washing.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of embodiments of the disclosed subject matter will become apparent as the following Detailed Description proceeds, and upon reference to the Drawings, where like numerals depict like parts, and in which:

FIG. 1 is a perspective view of a vehicle incorporating touch sensor assemblies consistent with the present disclosure;

FIG. 2 is a partial view of the interior cabin area of the vehicle of FIG. 1;

FIG. 3 is a block diagram of a touch sensor system that may be utilized in the vehicle of FIG. 1;

FIG. 4 is a perspective view a touch sensor assembly;

FIG. 5 is an exploded view of the touch sensor assembly of FIG. 4;

FIG. 6 is a rear perspective view the touch sensor assembly of FIG. 4 for mounting to an appliqué;

FIG. 7 is a rear perspective view the touch sensor assembly of FIG. 4 mounted to the appliqué of FIG. 6;

FIG. 8 is a sectional view of the appliqué and touch sensor assembly of FIG. 7 taken along the line 8-8 of FIG. 7;

FIG. 9 is a sectional view of the appliqué and touch sensor assembly of FIG. 7 taken along the line 9-9 of FIG. 7;

FIG. 10 is a cross-sectional view of the touch sensor assembly of FIG. 4;

FIG. 11 is a cross-sectional view illustrating mounting of a light emitting diode of FIG. 10;

FIG. 12 is a cross-sectional view of another embodiment for providing illumination to a touch area;

FIG. 13 is a diagram of capacitive circuitry having a capacitance responsive to contact by a user;

FIG. 14 is a plot of voltage vs. time illustrating the output of an exemplary touch sensor using capacitive circuitry during a touch and non-touch event;

FIG. 15 includes of plots of voltage vs. time for the outputs of two different touch sensors;

FIG. 16 is a flow chart of operations consistent with an embodiment to enable a multiple touch area command;

FIG. 17 illustrates another embodiment having a reference electrode disposed between two touch areas;

FIG. 18 is a flow chart of operations consistent with another embodiment utilizing the reference electrode of FIG. 17 to enable a multiple touch area command;

FIG. 19 is a perspective view of a steering wheel and a portion of an instrument panel;

FIG. 20 is a cross-sectional view of the raised dome of the sensor cover of FIG. 19;

FIG. 21 is a representational cross-sectional view of the raised dome of the sensor cover of FIG. 19 in a depressed position;

FIG. 22 is a diagram of a touch area pad consistent with another embodiment;

FIG. 23 is a flow chart of operations associated with the touch area pad of FIG. 22;

FIG. 24 is a diagram of a touch area pad and a switch of yet another embodiment;

FIG. 25 is a block diagram of a touch sensor system with memory that may be utilized in the vehicle of FIG. 1;

FIG. 26 is a flow chart of operations illustrating a function of the memory of FIG. 25;

FIGS. 26A and 26B are timing diagrams illustrating quiescent and active response times of a system with memory;

FIGS. 28A and 28B are timing diagrams illustrating relatively rapid key presses and associated memory output;

FIGS. 29A and 29B are flow charts of operations illustrating responses to single key presses for keys that are not multifunction keys and multifunction keys, respectively;

FIGS. 30A and 30B are timing diagrams illustrating single key presses of multifunction keys and associated memory outputs;

FIGS. 31A and 31B are flow charts of operations illustrating responses to multiple key presses with overlap between key presses;

FIGS. 32A and 32B are timing diagrams illustrating multiple overlapping non-multifunction key presses;

FIGS. 33A and 33B are timing diagrams illustrating multiple overlapping multifunction key presses

FIGS. 34A and 34B are timing diagrams illustrating multiple overlapping key presses for multifunction and non-multifunction keys;

FIGS. 35A and 35B are timing diagrams illustrating multiple overlapping key presses for multifunction keys that are released before the DK timer expires;

FIG. 36 is a timing diagram illustrating a valid multiple multifunction key press;

FIG. 37 is another illustrative touch sensor assembly portion including a visual indicator, an illumination source and an anti-swipe key;

FIG. 38 is a flow chart of operations illustrating functions of the anti-swipe (AS) key;

FIG. 39 is a timing diagram illustrating an output when only the AS key is pressed;

FIGS. 40 and 41 are timing diagrams illustrating the effect of pressing the AS key while a multifunction key is pressed;

FIG. 42 is a timing diagram illustrating the effect of pressing a multifunction key while pressing the AS key;

FIG. 43 is a timing diagram illustrating the effect of pressing the AS key while pressing multiple multifunction keys before the DK timer expires; and

FIG. 44 is a timing diagram illustrating the effect of pressing the AS key after the DK timer has expired.

Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art. Accordingly, it is intended that the claimed subject matter be viewed broadly.

DETAILED DESCRIPTION

Embodiments presented herein are described with reference to an automotive application. It is to be understood, however, that the embodiments described herein are presented by way of illustration, not of limitation. For example, a touch sensor system consistent with the present invention may be used in any of a variety of systems, e.g. in consumer and industrial equipment or appliances, for enabling a user input to switch or control functions and/or to input data.

FIGS. 1 and 2 illustrate a touch sensor assembly consistent with the present disclosure utilized at the exterior and interior of a vehicle 100. A touch sensor assembly consistent with the present disclosure may, for example, be provided as a user interface portion of a keyless vehicle entry system. Keyless entry systems are well-known and generally allow a user to unlock a door, e.g. a vehicle or building door, by entering a code on a user interface associated with the door. An output of the user interface may be provided to a controller configured to unlock the associated door upon entry of a predefined code at the user interface. In vehicle entry system, a touch sensor assembly 102 consistent with the present disclosure may be affixed on or proximate the B-pillar area 130 of the vehicle, as shown in FIG. 1. In addition, or alternatively, a touch sensor assembly 102 consistent with the present disclosure may be located on the front door 186 proximate a door handle 188. As shown in FIG. 2, one or more touch sensors 102 may be located on a vehicle steering wheel 202 and/or on the inside arm rest portion 204 of the driver's side door. A touch sensor consistent with the present disclosure may also be provided on a surface of the instrument panel.

FIG. 3 illustrates in block diagram form one exemplary embodiment of a touch sensor system 300 including a touch sensor assembly 102, a controller 302, and one or more vehicle systems 306, 308, 310 coupled to the controller 302. The touch sensor assembly 102 may include one or more known touch sensors, e.g. employing resistive sensing, capacitive sensing, acoustic sensing, magnetic sensing, optical sensing, etc., to provide an output in response to contact with a touch area. Combinations of touch sensors may be used to provide redundancy.

In operation, a user may cause contact, either directly or indirectly, with one or more of the touch areas, causing the assembly 102 to provide an associated output. The output of the assembly 102 may be coupled, e.g. via a vehicle CAN bus, to the controller 302. The controller may be responsive to the output to control one or more systems, e.g. vehicle door lock(s), vehicle security system 308, and/or another system 310, such as a vehicle sound system, climate control system, etc. For example, in an embodiment wherein the touch sensor system 300 is configured as a vehicle entry system, the controller 315 may be responsive to signals from the assembly 102 to control the vehicle door locks 305 to lock or unlock one or more doors.

FIG. 4 is a perspective view of one exemplary embodiment 102 a of a touch sensor assembly that may be installed at the exterior of a vehicle, e.g., on the B-pillar or adjacent a door handle as shown in FIG. 1, for use in connection with a vehicle entry system. The touch sensor assembly 102 a may include a sensor cover 402 visible to a user. The sensor cover 402 may identify a plurality of touch areas using alpha-numeric and/or other graphics. In the illustrated exemplary embodiment, a first touch area 420 is indicated by numerals 1 and 2, a second touch area is indicated by numerals 3 and 4, a third touch area 424 is indicated by numerals 5 and 6, a fourth touch area 426 is indicated by numerals 7 and 8, and a fifth touch area 428 is indicated by numerals 9 and 0.

As shown in the exploded view of FIG. 5, each of the touch areas 420, 422, 424, 426, and 428 may be associated with a corresponding touch sensor 430, 432, 434, 436, and 438, respectively, whereby contact with the surface of the sensor cover in a touch area causes the corresponding touch sensor to provide an associated output. The touch sensors may be disposed on a printed circuit board (PCB) 404, carrying conductive traces for providing sensor outputs to associated contacts 403.

The PCB 404 and the sensor cover 402 may be configured to be received at least partially within a housing 406 with the PCB disposed between the housing 406 and the sensor cover 402. The housing 406 include a plurality of pins 502 each of which is electrically connected to a corresponding one of the pins 403. The pins 502 may extend to a connector portion 440 for electrically coupling the touch sensor assembly 102 a to other components such as the controller 302 of FIG. 3.

FIG. 6 is an exploded view of an assembly touch sensor assembly 102 a and a housing cover 602. The housing cover 602 may, for example, be an appliqué attached to the B-pillar area 130 of a vehicle or to the trim area of the front door 186 proximate the front window 180. The housing cover 602 may include a plurality of screw bosses 610, 612, 614, and 616 configured to accept a corresponding plurality of screws 640, 642, 644, and 646 to assist in securing the touch sensor assembly 102 a to the rear surface 603 of the housing cover 602. The rear surface 603 of the housing cover 602 may also include a projection 604 configured to mate with a corresponding slot in the housing 406 of the touch sensor assembly 102 a. In one embodiment, the projection 604 may be an upstanding wall defining a closed geometry.

The rear surface 603 of the housing cover 602 may include a portion 605 adjacent to the top surface of the sensor cover 402 when the touch sensor assembly 102 a is mounted to the housing cover 602. This portion 605 of the housing cover 602 may formed of a sufficiently translucent material to allow viewing of the touch area indicators on the sensor cover when housing cover 602 is coupled to the assembly. The translucent material may be selected so that the touch area indicators on the sensor cover 402 are not readily visible to user unless illuminated by a light source of the switch assembly 102 a. In this way, the housing cover 602 may mask the sensor cover 402 until the touch sensor assembly 102 a is activated, e.g., by touching the housing cover 602 at a position above one of the touch areas.

FIG. 7 is a rear perspective view of the touch sensor assembly 102 a mounted to the rear surface 603 of the housing cover 602. FIG. 8 is a sectional view of the housing cover 602 and touch sensor assembly taken along the line 8-8 of FIG. 7. As shown in FIG. 8, the rear surface of the housing cover 602 may contact the top surface of the sensor cover 402 to minimize the distance between the housing cover and the sensing circuitry of the PCB 404. The rear surface of the sensor cover 402 may contact the touch sensors on the PCB 404. The upstanding wall 604 of the housing cover 602 may be configured to mate with an associated slot 803 of the housing 406. A channel 802 may be provided in the bottom of the slot 803 to accept a gasket and/or an adhesive, for example epoxy, glue, etc. The gasket and/or adhesive may form a seal between the upstanding wall 604 of the housing cover 602 and the associated slot 803. Turning to FIG. 9, there is provided a sectional view of the housing cover 602 and touch sensor assembly taken along the line 9-9 of FIG. 7. As shown, the sensor cover 402 may include projections 940, 942 to mate with associated portions of the housing 406, e.g. through a snap-fit connection. When the housing cover 602 is properly mounted to the housing 406, a cavity 806 defined by the rear surface 603 of the housing cover 602 and the top surface of the housing 406 may be formed. The cavity 806 may be substantially water tight, and the PCB 404 and the sensor cover 402 may be completely disposed within the cavity 806.

FIG. 10 is a perspective and cross-sectional view of the touch sensor assembly 102 a. As shown, a light emitting diode (LED) 1000, 1002, 1004, 1006, and 1008 may be positioned beneath each of the touch areas 420, 422, 424, 426, and 428 of the sensor cover 402 to provide illumination. Each LED may be mounted to a bottom surface of the PCB 404. FIG. 11, for example, illustrates positioning of the LED 1008 relative to the touch area 428. As shown, the LED may be mounted to the bottom surface 1012 of the PCB 404 with the illumination surface of the LED 1008 spaced a distance x from the touch area 428 to be illuminated. This distance x may be selected depending on the application to achieve a desired illumination coverage area for the touch area 428.

FIG. 12 illustrates another LED mounting configuration for providing illumination of the touch areas of the sensor cover 402. In the exemplary embodiment of FIG. 12, the LED is mounted to the bottom surface 1012 of the LED with the illumination surface 1010 of the LED at a distance x1 from the touch area to be illuminated. To maximize the distance x1 to achieve illumination over the length L of the touch area, the thickness d of the sensor cover 402 may be adjusted (e.g. minimized) and the sensor cover may be separated from the PCB by a distance x2. Since separation of the sensor cover 402 from the PCB 404 may adversely affect the capacitive coupling of a touch on the touch area 428 to the associated touch sensor 438, one or more conductors, e.g. conductors 1202 and 1204, may be provided for conductively coupling sensor cover 404 to the touch sensor 438.

In yet another embodiment, one or more of the LEDs may function both as light source and a light sensor to sense an ambient light level, or a separate LED may be provided for sensing ambient light levels. A signal representative of the sensed ambient light may be provided from an LED to an associated controller, e.g., controller 302, which may adjust the light output established by one or more of the LEDs in response thereto. When the touch sensor assembly is not in use, the controller may not drive the LEDs to disable illumination of the sensor cover. When the user touches a touch area, the controller may energize the LEDs to illuminate the touch areas. If the user touches a touch area during high ambient light conditions such as daylight, the controller may drive the LEDs to achieve maximum illumination of the touch areas so the user can read each of the touch areas even in direct sunlight. If the user touches a touch area during low ambient light conditions such as at night, the controller may drive the LEDs to illuminate the sensor cover at a comparatively lower level to provide appropriate light contrast for the user. The controller, e.g., controller 302, may be a component of the touch sensor assembly 102 a so that light sensing and regulation may be accomplished within the touch sensor assembly 102 a to allow for direct substitution with an existing mechanical entry system.

FIG. 13 is a circuit diagram of one embodiment of an exemplary touch sensor 1300 useful in a touch sensor assembly consistent with the present disclosure. The touch sensor 1300 may include a plurality of switches S1, S3, S3, a sample capacitor Cs, and an unknown or variable capacitance Cx to be measured. The variable capacitance Cx may initially be the capacitance of the touch sensor 1302 to free space or to an electrical ground. The touch sensor 1302 may include a sense electrode which may further include spaced conductive traces (e.g., hard printed circuit board traces, thin or thick film flex circuitry) in a range of patterns to customize performance. The variable capacitance Cx may change with the proximity of an object thereto, e.g., a finger of the user, which may introduce a parasitic capacitance to ground. The switches S1, S2, and S3 may control charge transfer between capacitances Cx and Cs so that the voltage Vcs across capacitor Cs may be used as an indication of the value of capacitance Cx. Additional and other exemplary capacitive circuitries having a capacitance responsive to the proximity of an object thereto are described in detail in U.S. Pat. No. 6,466,036, the teachings of which are incorporated herein by reference.

FIG. 14 includes a plot of output voltage vs. time associated with the exemplary touch sensor of FIG. 13. The output of the sensor may be provided to a controller, e.g. controller 302, for controlling an associated function. As shown, if the output voltage maintains a reference voltage level 1408 a non-touch event is assumed. If the output voltage exceeds the negative detection threshold 1404 for a specified time interval, e.g., time interval t1, then a touch event is determined to have occurred for the associated touch area. In one embodiment, time interval t1 may be 250 milliseconds.

Inadvertent actuation may occur in capacitive touch circuitry applications. Inadvertent actuation may be exacerbated by environmental factors such as rain, frost, and condensation. In some instances, a user may touch one touch area and moisture on the touch areas may cause cross-talk with another touch area. An output voltage indicating a touch event on two touch areas may be provided.

To address such inadvertent actuation from cross-talk, touch sensing systems may utilize a touch area suppression algorithm. In one embodiment, a touch area suppression algorithm may identify signals that exceed a detection threshold for a necessary time interval, and compare such signals to each other to determine which signal exceeds the negative detection threshold by the largest difference. The touch area suppression algorithm may select the strongest signal, e.g., the signal that exceeds the detection threshold by the largest difference, and ignore the weaker signal. The touch area suppression algorithm may thus enable only one touch area to be detected at a time.

In applications where two touch areas must be simultaneously touched in order to initiate a particular function, it may be necessary to detect simultaneous touching of the touch areas. For example, in a keyless entry system application the system may be configured to allow locking all doors of a vehicle by simultaneously touching the fourth touch area 426 having numerals [7-8] and the fifth touch area 428 having numerals [9-0]. Such an operation may be prevented by a conventional touch area suppression algorithm, which may select only the strongest signal from one, but not both, touch areas. FIG. 15, for example, includes plots 1502, 1504 of voltage vs. time for capacitive touch sensors associated with the touch areas 428 and 426, respectively. In the illustrated embodiment, if touch areas 428 and 426 were simultaneously touched, a conventional touch area suppression algorithm may select the strongest signal, i.e. from touch area 426, and ignore the weaker signal from touch area 428.

FIG. 16 is a flow chart of operations 1600 of a algorithm consistent with an embodiment of the invention to enable a multiple touch area command while still utilizing a conventional touch area suppression feature. The flow charts set forth herein may include particular sequences of steps. It can be appreciated, however, that the sequence of steps merely provides an example of how the general functionality described herein can be implemented. Further, each sequence of steps does not have to be executed in the order presented unless otherwise indicated.

Also, it will be appreciated that the functionality described for the embodiments of the invention may be implemented by a controller, e.g. controller 302, or other system component using hardware, software, or a combination of hardware and software, and well-known signal processing techniques. If implemented in software, a processor and machine-readable medium is required. The processor may be any type of processor capable of providing the speed and functionality required by the embodiments of the invention. For example, the processor could be a processor from the Pentium® family of processors made by Intel Corporation, or the family of processors made by Motorola. Machine-readable media include any media capable of storing instructions adapted to be executed by a processor. Some examples of such media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), programmable ROM (PROM), erasable programmable ROM (EPROM), electronically erasable programmable ROM (EEPROM), dynamic RAM (DRAM), magnetic disk (e.g. floppy disk and hard drive), optical disk (e.g. CD-ROM), and any other device that can store digital information. In one embodiment, the instructions are stored on the medium in a compressed and/or encrypted format.

As used herein, the phrase “adapted to be executed by a processor” is meant to encompass instructions stored in a compressed and/or encrypted format, as well as instructions that have to be compiled or installed by an installer before being executed by the processor. Further, the processor and machine-readable medium may be part of a larger system that may contain various combinations of machine-readable storage devices through various I/O controllers, which are accessible by the processor and which are capable of storing a combination of computer program instructions and data.

With reference to FIG. 16, operation 1602 may start or enable a conventional touch area suppression algorithm. In operation 1604, a user may simultaneously touch two touch areas. If the associated signal for each touch area is below the negative detection threshold, then the touch area suppression algorithm may output a binary coded decimal (BCD) value for the particular touch area having the strongest signal. For example, assuming the two touch areas touched were the fourth touch area 426 having numerals [7-8] and the fifth touch area 428 having numerals [9-0] and the results were as depicted in FIG. 15, operation 1604 would determine that the signal associated with the fourth touch area 426 is stronger than the signal associated with the fifth touch area 428. Accordingly, the BCD value for the fourth touch area would be provided. Each touch area may have an associated BCD value and the BCD value for the fourth touch area 426 may be “110.”

Operation 1606 may determine if the strongest signal from operation 1604 is below the negative detection threshold for a specified time interval t1. In one embodiment, time t1 may be 250 milliseconds. If not, the operations may cycle back to operation 1602. If the strongest signal is less than the negative detection threshold for the specified time interval, then operation 1608 may check if another signal associated with a second touch area is also less than the negative detection threshold for the specified time interval. If not, then operation 1610 may continue to output the BCD value of operation 1604 until the touch area is released 1612.

If the second signal is also less than the negative detection threshold for the specified time interval, then operation 1614 may check if any other signal from any other third touch area also meets these criteria. If not, then the initial BCD value first output in operation 1604 may be changed to the BCD value associated with a particular function for the two touch areas simultaneously touched. For example, if the fourth touch area 426 having numerals [7-8] and the fifth touch area 428 having numerals [9-0] are simultaneously touched the BCD code value output in operation 1604 (e.g., “110”) would change to the BCD code value to lock all doors, e.g., “100.” If another signal associated with a third touch area is also less than the negative detection threshold for the specified time interval, then operation 1618 would do nothing and not output a BCD value until all touch areas returned to an untouched state and then would cycle back to start 1620.

Therefore, if both touch areas are touched resulting in associated signals, e.g., signals 1502 and 1504 of FIG. 15, that less than negative detection threshold for a specified time interval, e.g., time t1, then the associated function would be implemented. This could be the automatic locking feature for all doors if the fourth touch area 426 and the fifth touch area 428 are touched simultaneously. This improves the ability of the touch sensor assembly to address inadvertent touch area actuation from cross-talk while also allowing multiple touch area functions to be implemented. Although the above operations 1600 are detailed with respect to pressing two touch areas simultaneously, those skilled in the art will recognize that similar operations could be performed to check for simultaneous touching of three or more touch areas.

Another example of a multiple touch area command in a touch sensor assembly is the enable/disable of an auto lock feature. In this example, the user may first touch and hold the fourth touch area 426 having numerals [7-8]. The BCD value associated with the fourth touch area may be output and the user may then touch the second touch area 422 having numerals [3-4] while still simultaneously touching the fourth touch area 426. If both the signals for the second 422 and fourth touch areas 426 are less than the negative detection threshold for the specified time interval, the BCD value for the second step of the auto lock enable/disable feature may be output even if the touch area suppression algorithm is enabled.

FIG. 17 illustrates another embodiment consistent with the present invention having a reference electrode incorporated into the touch sensor assembly and disposed between two touch areas. The reference electrode may be disposed between any two of the five touch areas 1720, 1722, 1724, 1726, or 1728 that may be touched simultaneously to activate a desired function. In the embodiment of FIG. 17, the reference electrode 1702 is illustrated between the fourth touch area 1726 having numerals [7-8] and the fifth touch area 1728 having numerals [9-0].

FIG. 18 illustrates flow chart of an algorithm associated with the touch sensor assembly of FIG. 17 having the reference electrode 1702 disposed between the fourth touch area 1726 and fifth touch area 1728. Many operations of the algorithm of FIG. 18 are similar to FIG. 16 and are labeled as such. Accordingly, any repetitive descriptions are omitted herein for clarity. The main difference comparing operations 1800 to operations 1600 are that operations 1800 use a reference signal from the reference electrode 1702 and are for two specific touch areas (the fourth touch area 1726 and fifth touch area 1728) and a specific door lock function, as opposed to generic touch areas and a generic function of operations 1600.

If all three signals associated with the fourth touch area 1728, fifth touch area 1728, and the reference electrode 1702 are less than a negative detection threshold for the specified time interval t1, then the doors do not lock 1818 and the system waits until the signals associated with the fourth touch area 1726, the fifth touch area 1728, and the reference electrode 1702 return to a low state. If the fourth signal and fifth signal are less than the negative detection threshold for the specified time interval t1, and the reference signal is not, then the BCD value is changed to the lock door code 1816. Thus, the reference electrode 1702 and its associated signal further protect against an inadvertent operation of a multi touch area operation such as the door lock operation.

Inadvertent actuation of touch areas and lack of tactile feedback for a user are considerations when designing touch sensor assemblies utilizing capacitive sensing circuitry. Inadvertent actuation of touch areas may occur if a person passes their finger over touch areas when trying to locate an intended touch area. It would be desirable to prevent actuation of the functions associated with the unintended touch areas as the user attempts to locate the intended touch area. This inadvertent actuation may be more likely to occur in a system application where there are multiple touch areas in close proximity to one another. Providing tactile feedback to the user to indicate that the touch area has been selected may also be desirable in certain instances.

FIG. 19 illustrates another embodiment of the present invention to address inadvertent actuation of touch areas and to provide tactile feedback to a user when using a touch sensor assembly having capacitive sensing circuitry. Those skilled in the art will recognize many other system applications. The system of FIG. 19 includes touch sensor assemblies 1980 and 1982 coupled to a steering wheel 1900 of a vehicle. The right touch sensor assembly 1982 may include a first touch area 1950 for a phone, a second touch area 1952 for an increase in radio volume, a third touch area 1954 for a decrease in radio volume, and a fourth touch area 1956 for a right blinker of the vehicle. Advantageously, the sensor cover 1902 of the right touch sensor assembly 1982 may have a raised portion over each touch area 1950, 1952, 1954, and 1956. The raised portion of the sensor cover 1902 may be in the form of a raised dome.

FIG. 20 is a cross-sectional view of a raised dome 1912 of the sensor cover 1902 for the first touch area 1950. The raised dome portion 1912 of the sensor cover 1902 may have a height dl above the touch sensor 1906 of the associated touch sensor for that touch area 1950. Therefore, if a user passes a finger or other object over the raised dome 1912 the height dl of the raised dome will maintain the user's finger a sufficient distance from the touch sensor 1906 to help avoid an inadvertent actuation of the first touch area 1950 function.

FIG. 21 illustrates a representational view of the raised dome 1912 of FIG. 20 in a depressed or deformed position when the first touch area 1950 is the intended touch area to be selected by the user. When a user applies downward pressure to the raised dome 1912, the raised dome 1912 temporarily collapses to allow the actuation of the first touch area 1950 function. When the user removes the pressure, the raised dome 1912 may return to its position of FIG. 20. In addition to enhancing protection against inadvertent actuation of touch areas, the raised dome 1912 may also advantageously provide tactile feedback to a user. The raised dome 1912 may be incorporated into the sensor cover 1902 to minimize components. Alternatively, the raised dome 1912 may be provided as a separate structure from the sensor cover 1902.

FIG. 22 illustrates a touch area pad 2200 having a plurality of touch areas for numerals 1-9. Each touch area may have an associated touch sensor located beneath the touch area. The proximity of the touch areas to each other may cause outputs from touch sensors associated with unintended touch areas as a user moves to touch an intended touch area. For example, a user may intend to touch area numeral 5 and may pass by touch area numerals 4 and 7 before reaching touch area numeral 5. A touch sensor associated with numerals 4 and 7 may detect a change in capacitance. Even if a user touches a touch area on the outside perimeter of the touch area pad 2200, e.g., adjacent touch area numeral 7, other circuitries associated with other touch areas may exhibit a sensed change in capacitance.

FIG. 23 illustrates operations 2300 of an algorithm consistent with another embodiment to assist with inadvertent actuation of touch areas in systems such as the touch area pad of FIG. 22. Operation 2302 may monitor the change in capacitance for circuitries associated with all touch areas, e.g., all touch area numerals 1-9 of FIG. 22. Operation 2304 may analyze if any cross-talk is occurring. Cross-talk may be, for example, a change in capacitance of any two or more capacitive touch sensing circuitries. If no cross-talk is occurring, then no signal is output and the operations 2300 continue to monitor the change in capacitance associated with all the touch areas. If there is cross-talk, then the strongest signal is determined and the function or output associated with the strongest signal may be executed 2306. For example, during a touch of intended touch area numeral 5, some neighboring touch areas may have associated circuitries that sense a higher than normal change in capacitance. The change in capacitance for those circuitries may not be as high as the change in capacitance for the intended touch area numeral 5 which therefore helps confirm that touch area numeral 5 is the intended touch area.

FIG. 24 illustrates yet another embodiment consistent with the present invention having a touch area pad 2400 coupled to an electromechanical switch 2404. In the embodiment of FIG. 24, a user would make a selection of one of the touch areas for numerals 1-9 using the touch area pad 2400. The touch area pad 2400 may provide feedback, e.g., audio or visual, to the user to indicate the selected touch area. If highlighted selected touch area is indeed the intended touch area, the user may then press the electromechanical switch 2404 for final activation of the selected touch area. The electromechanical switch 2404 may therefore provide another measure against unintended switch activations.

FIG. 25 illustrates in block diagram form another embodiment of a touch sensor system 2500 consistent with the present disclosure. The touch sensor system 2500 may include the touch sensor assembly 102, the controller 302, and one or more vehicle systems 306, 308, 310 coupled to the controller 302. The touch sensor system 2500 may further include a memory 2504 coupled to the controller 302. In an embodiment, the memory 2504 may be implemented in hardware, software, firmware or a combination thereof. In another embodiment, the memory 2504 may be implemented using discrete and/or integrated components as should be known by those of ordinary skill in the art. For example, the memory 2504 may be cache memory.

The memory 2504 may be configured to receive and store a value, e.g., a code, representing a valid touch sensor touch. A valid touch sensor touch may be understood as corresponding to a touch sensor output signal that exceeds a threshold for a necessary time interval as discussed above. For example, a value representing a valid touch sensor touch may be a result of a touch area suppression algorithm. The memory 2504 may be further configured to output each value. In an embodiment, the memory 2504 may be configured to output each value in the order in which it was received, i.e., FIFO (first in, first out).

The memory 2504 may be configured to receive and store a plurality of codes representing a plurality of key presses and to output the codes in the order received. As used herein, “key” corresponds to a touch sensor touch area and “key press” corresponds to a detected touch sensor touch, i.e., detected contact with a touch area. In this manner, memory 2504 may provide a buffer between key presses and output codes that may accommodate relatively rapid sequential key presses without loss of data. For example, a user may press keys in a sequence relatively rapidly, e.g., an unlock vehicle door sequence. The touch sensor system 2500 may be configured to output codes corresponding to key presses at a rate that may depend on a communication protocol. For example, the output rate may depend on a time interval. The time interval may include an output hold time interval and/or an output low state hold time interval. A code corresponding to a key press may be applied to an output for the output hold time interval. The output hold time interval may be followed by an output low state hold time interval. Each interval may have a minimum duration that may depend on the communication protocol. In some situations, the output rate may be slower than the rate of sequential key presses. In other words, the output hold time interval and/or output low state hold time interval may be longer than a key press duration required for a valid touch sensor touch. Memory 2504 may receive and store codes corresponding to key presses at the relatively rapid rate and output the codes at the slower rate. Memory 2504 may be configured to store a number of codes representing key presses. For example, the maximum number of codes may be ten.

FIG. 26 illustrates an exemplary flow chart 2600 for operations of a memory, e.g., memory 2504. The memory may receive a code representing a pressed key 2602. For example, the code may be provided by a controller, e.g., controller 302. In an embodiment, the code may be a binary coded decimal (BCD) representation of a number associated with a particular touch area. The code may then be stored in the memory 2604. The code may then be output from the memory 2606. In an embodiment, a code may be output from the memory in the order that it was received and stored in the memory.

In some embodiments, a response time, i.e., a time interval for a key press to be detected, interpreted, provided to memory and output from memory initiated, may depend on a state of a touch sensor system, e.g., touch sensor system 2500. For example, the states of the touch sensor system 2500 may include a quiescent state and an active state. The quiescent state may be a relatively low power consumption state and may be initiated after a period without key presses and/or in response to a particular combination of key presses. For example, a combination of key presses corresponding to a lock doors command may initiate the quiescent state. The active state may be initiated from the quiescent state by, e.g., a key press after a period of no key presses. The response time for a system in the quiescent state may be relatively greater than the response time for a system in the active state.

FIGS. 27A and 27B are timing diagrams illustrating response times from an exemplary quiescent state and an exemplary active state, respectively. A response may be initiated by a key press 2702 of sufficient duration. The key may remain pressed for a key press time interval and may then be released 2704. Referring to FIG. 27A, if the key press time interval is greater than the quiescent response time, a code corresponding to the key may be output from memory at the completion of the quiescent response time 2706 a. The code may be applied to the output for an output hold time 2708. For the example shown, the output hold time may be followed by an output low state hold time 2710. Referring to FIG. 27B, if the key press time interval is greater than the active response time, a code corresponding to the key may be output from memory at the completion of the active response time 2706 b.

FIGS. 28A and 28B are timing diagrams illustrating exemplary relatively rapid key presses and associated memory outputs. FIG. 28A illustrates presses of different keys in succession and FIG. 28B illustrates presses of the same key in succession. In each of FIG. 28A and FIG. 28B, a first key press time interval 2802 includes a quiescent response time 2706 a while subsequent key press time intervals 2804, 2806 include an active response time. As discussed above, based on the buffering function of a memory, a code corresponding to each key press may be output 2708 and no key press may be missed. In other words, a code corresponding to each key press may be output at a lower rate than the key press rate, i.e., each key press time interval may be smaller than an output hold time interval. Each output code 2708 may be followed by an output low state 2710.

FIGS. 29A and 29B illustrate flow charts for single key press operations, i.e., operations where a single key is pressed and a code corresponding to the single key may be output before a second key may also be pressed. Generally, a sequence of single key presses may signal a command, e.g., unlock a vehicle door. In some applications, a touch sensor system, e.g., touch sensor system 2500, may include “multifunction” keys. A multifunction key may be understood as a key that when pressed while another multifunction key is pressed, causes a touch sensor system to output a code corresponding to a combination of the multifunction keys. For example, pressing a plurality of multifunction keys, substantially simultaneously, may signal a command, e.g., lock all vehicle doors. Each multifunction key may also be used individually in a sequence of single key presses to signal a command.

FIG. 29A illustrates a flow chart 2900 for single key operations for keys that are not multifunction keys. A user may press a key that is not a multifunction key 2902. A code corresponding to the pressed key may be output 2904 to a memory, e.g., memory 2504. The code may be output to the memory after a time interval corresponding to a time required to detect the key press and determine the appropriate code. For example, the time interval may be included in the active response time. The code may then be received by, stored in and output from, memory, e.g., according to flow chart 2600. FIGS. 27A and 27B illustrate examples of timing diagrams associated with single key operations for keys that are not multifunction keys.

The illustrated timing diagrams include key press intervals, response time intervals where a response time interval is either a quiescent response time interval or an active response time interval and associated output hold time intervals.

FIG. 29B illustrates a flow chart 2910 for single key operations for multifunction keys. A user may press a multifunction key 2912. A single key (SK) timer may then start 2914. A code corresponding to the multifunction key may then be provided to memory if either the multifunction key is released and the SK timer has not expired or the SK timer expires 2916. FIGS. 30A and 30B illustrate examples of timing diagrams corresponding to single multifunction key operation. FIG. 30A and FIG. 30B illustrate a multifunction key press 2702 and a SK timer start 3006 after the quiescent response time 2706 a. Although not shown, operation in the active mode is similar. In the active mode, the SK timer may start after the active response time interval initiated by the key press 2702. FIG. 30A illustrates a code output when the multifunction key is released 2704 and the SK timer has not expired. FIG. 30B illustrates a code output when the SK timer expires and the multifunction key remains pressed. As shown in FIG. 30B, when the multifunction key is released 2704 after the SK timer has expired, there may not be additional output.

FIG. 31A illustrates a flow chart 3150 for multiple key operations, i.e., a user presses a first key and a second key without first releasing the first key 3152. Whether the first key pressed is a multifunction key may be determined 3154. Whether the second key pressed is a multifunction key may then be determined 3156. An output may then be provided based on the determinations 3158. The output may correspond to a single key and/or a combination of multifunction keys.

FIG. 31B illustrates another flow chart 3100 for multiple key operations, i.e., a user presses a first key and a second key without first releasing the first key 3102. Whether the first key pressed is a multifunction key may then be determined 3104. If the first key pressed is not a multifunction key, a code associated with the first key may be output to memory 3110. While both keys remain pressed, the system may wait for a key to be released 3112. When a key is released, a code corresponding to the second key may be output to memory 3114, if the second key remains pressed, i.e., the second key was not the key released. If the second key is released, no additional codes may be output to memory.

FIGS. 32A and 32B illustrate examples of pressing a first key and a second key without first releasing a first key for keys that are not multifunction keys. As shown in FIG. 32A, a first key may be pressed 2702 a. The first key may be pressed for at least a quiescent response time interval. A code corresponding to the first key may be output to memory. Code output from memory 2708 a may be initiated after the quiescent response time interval. A second key may then be pressed 2702 b, e.g., during an output hold time interval. While both keys are pressed, there may be no further output to memory. The first key may then be released 2704 a, e.g., after the output low state hold time interval. A code corresponding to the second key may be output to memory and then may be output from memory 2708 b. The second key may then be released 2704 b. No further codes may be output to memory for this key sequence.

FIG. 32B illustrates another multiple key sequence for keys that are not multifunction keys. The first key may be pressed 2702 a and its corresponding code may be provided to, and output from, memory 2708 a. The second key may then be pressed 2702 b. While both keys are pressed, there may be no further output to memory. The second key may then be released 2704 b. Release of the second key may not result in an output from memory. The first key may then be released 2704 a without triggering an additional output.

Turning again to FIG. 31, if the first key pressed is a multifunction key, a single key (SK) timer may be started and the system may then wait, i.e., no output, for a second multifunction key to be pressed 3120. If a second key is not pressed and the SK time expires, a code corresponding to the first multifunction key may be output to memory 3122. If a second key is pressed, whether the second key is a multifunction key may be determined 3124. If the second key is not a multifunction key, the system may wait for a key to be released 3126. If the key released is the first multifunction key, a code corresponding to the second key may be output to memory 3126. If the second key is a multifunction key, a dual key (DK) timer may be started 3128. Whether either multifunction key is released may then be determined 3130. If a multifunction key is released and the SK timer has not expired, a code corresponding to the pressed key may be output to memory when the SK timer expires 3132. If a multifunction key is not released, i.e., both keys remain pressed, and the DK timer expires, a code corresponding to a combination of multifunction keys may be output to memory 3134.

FIGS. 33A, 33B, 34A, 34B, 35A, 35B and 36 illustrate timing diagrams for examples of key press sequences where a first key pressed is a multifunction key and a second key is pressed without first releasing the first multifunction key. The second key may or may not be a multifunction key. FIGS. 33A and 33B illustrate key press sequences where a first multifunction key is pressed 2702 a, an SK timer starts, runs and expires, and then a second multifunction key is pressed 2702 b. As illustrated in both diagrams, a code corresponding to the first multifunction key is output 2708 a when the SK timer expires. In FIG. 33A, both multifunction keys are released 2704 a, 2704 b prior to a DK timer expiring, without additional output. In FIG. 33B, both multifunction keys are released 2704 a, 2704 b when the DK timer expires, and a code corresponding to a combination of multifunction keys is output 3308.

FIGS. 34A and 34B illustrate timing diagrams for examples of key press sequences where the second key that is pressed is not a multifunction key. In both examples, a multifunction key is pressed 2702 a, an SK timer starts then the second key is pressed 2702 b. In FIG. 34A, the multifunction key is released 2704 a prior to the SK timer expiring. A code corresponding to the second key is then output 2708 b. The second key is then released 2704 b with no additional output. In FIG. 34B, the second key is released 2704 b prior to the SK timer expiring. When the SK timer expires, a code corresponding to the first multifunction key is output 2708 a. The first multifunction key is then released 2704 a, without additional output.

FIGS. 35A and 35B illustrate timing diagrams for examples of key press sequences where the first and second keys are both multifunction keys, one key is released before the SK timer expires and one key is released after the SK timer expires. In FIGS. 35A and 35B, the first multifunction key is pressed 2702 a, an SK timer starts, then the second key is pressed 2702 b. In FIG. 35A, the first key is released 2704 a, then the SK timer expires and a code corresponding to the second multifunction key is output 2708 b then the second key is released 2704 b. In FIG. 35B, the second key is released 2704 b, then the SK timer expires and a code corresponding to the first multifunction key is output 2708 a then the first key is released 2704 a.

FIG. 36 illustrates a timing diagram for an example of a key press sequence where both keys are multifunction keys. The first multifunction key is pressed 2702 a, an SK timer starts, then the second multifunction key is pressed 2702 b and the DK timer starts. The SK timer expires while both keys are pressed. The DK timer then expires and a code corresponding to the combination of multifunction keys is output 3308. Both keys are then released 2704 a, 2704 b without additional output.

FIG. 37 illustrates a top perspective view of an embodiment of a touch sensor assembly 3702 consistent with the present disclosure. The touch sensor assembly 3702 may include a plurality of touch areas 420, 422, 424, 426, 428. Each touch 420, 422, 424, 426, 428 area may have an associated illumination source 1000, 1002, 1004, 1006, 1008, configured to illuminate the touch areas. Each illumination source may be disposed beneath its associated touch area, e.g., as discussed above. For example, each illumination source may be an LED.

The illumination sources 1000, 1002, 1004, 1006, 1008, may be configured to be activated based on a detected contact with a touch area. For example, contacting any one of the plurality of touch areas 420, 422, 424, 426, 428, may result in the activation of the plurality of illumination sources 1000, 1002, 1004, 1006, 1008 thereby illuminating the plurality of touch areas.

In an embodiment, the touch sensor assembly portion 3702 may include a visual indicator 3704. The visual indicator 3704 may be configured to provide visual feedback to a user that a touch of a touch area, i.e., contact with the touch area, has been detected. For example, the visual indicator may be an LED. The visual indicator 3704 may be activated when contact with any of the plurality of touch areas 420, 422, 424, 426, 428 is detected. The visual indicator 3704 may be disposed adjacent the first touch area 420. The first touch area 420 may correspond to a first key, e.g., 1-2 key.

In an embodiment, the touch sensor assembly 3702 may include an anti-swipe (AS) touch area 3706. The AS touch area 3706 may be disposed adjacent the fifth touch area 428. The fifth touch area 428 may correspond to a fifth key, e.g., 9-0 key. The AS touch area 3706 may include a raised area that may not include numerical designators and may not include visual indicators other than the raised area. The AS touch area may be configured to reduce the likelihood of inadvertent activation of a function triggered by a combination of multifunction keys. For example, in some embodiments, contacting both the fourth touch area, e.g., touch area 426, and the fifth touch area, e.g., touch area 428, may command a vehicle's doors to lock. These touch areas could both be inadvertently contacted during car washing, for example. Contacting the AS touch area and the fourth and fifth touch areas may prevent an output commanding a vehicle's doors to lock and may therefore prevent inadvertent door locking.

FIG. 38 illustrates a flow chart 3800 for AS touch area (AS key) operation. Program flow may begin with an AS key being pressed 3802. Whether any other keys are pressed may be determined 3804. If no other keys are pressed, no output may be generated 3806. Unlike the plurality of touch areas, e.g. touch areas 420, 422, 424, 426, 428, pressing the AS key may not activate a visual indicator, e.g., visual indicator 3704, and may not activate the illumination sources 1000, 1002, 1004, 1006, 1008. If other keys are pressed, whether multiple multifunction keys are pressed may be determined 3810. If multiple multifunction keys are not pressed, i.e., none or one is pressed, the AS key may be ignored 3812. If multiple multifunction keys are pressed and a DK timer expires, an output based on a combination of multifunction keys may be prevented 3814.

FIGS. 39 through 44 illustrate timing diagrams for examples of key press sequences and/or key press combinations for embodiments of touch sensor assemblies that include an AS key. FIG. 39 illustrates a timing diagram for contacting only the AS key. Contacting and/or releasing only the AS key may not produce an output and may not activate a visual indicator.

FIGS. 40 and 41 illustrate timing diagrams corresponding to the AS key being pressed while a single multifunction key is pressed. In FIG. 40, the AS key is pressed while the multifunction key is pressed and both keys are released before the SK timer expires. In this example, a code corresponding to the multifunction key may be output when the keys are released. In other words, the AS key has no effect. In FIG. 41, the AS key is pressed while the multifunction key is pressed and both keys are released after the SK timer expires. In this example, a code corresponding to the multifunction key may be output when the SK timer expires. The AS key has no effect.

FIG. 42 illustrates a timing diagram corresponding to a multifunction key being pressed after the AS key is pressed. Pressing the AS key does not produce an output. Pressing the multifunction key starts an SK timer. Both keys are released before the SK timer expires. In this example, a code corresponding to the multifunction key may be output when the keys are released. The AS key has no effect.

FIGS. 43 and 44 illustrate timing diagrams corresponding to pressing the AS key while a first multifunction key and a second multifunction key are pressed. In FIG. 43, the AS key is pressed while the DK timer is running, i.e., after the first and second multifunction keys are both pressed and before the DK timer expires. The keys are released some time later. In this example, no output is produced. In other words, pressing the AS key while the DK timer is running and prior to its expiration, prevents a code corresponding to the combination of multifunction keys from being output. In FIG. 44, the AS key is pressed after the DK timer expires and the keys are released some time later. In this example, the AS key has no effect. A code corresponding to the combination of multifunction keys is output when the DK timer expires. When the AS key is pressed, the code corresponding to the combination of multifunction keys has been output.

In summary, there is provided a touch sensor assembly. The touch sensor assembly may include a housing, a circuit board configured to be received at least partially in the housing, at least one touch sensor coupled to the circuit board, and a sensor cover configured to be received at least partially in the housing with the circuit board disposed between the housing and the sensor cover. The sensor cover includes a graphical indicator of a touch area associated with the at least one touch sensor. The housing includes a mating feature configured to mate with a corresponding feature on a rear surface of an housing cover to provide a substantially water tight cavity for enclosing the circuit board and the sensor cover between the housing and the housing cover.

According to another aspect, there is provided a touch sensor assembly including a touch sensor configured to provide an output in response to contact with a touch area, and a raised dome portion positioned over the touch area. The raised dome may be configured to provide tactile feedback to a user if the user depresses the raised dome.

According to another aspect, there is provided a touch sensor assembly including a touch sensor configured to provide an output in response to contact with a touch area, a sensor cover configured to at least partially cover the touch sensor, the sensor cover including a graphical indicator identifying a position of the touch area; and at least one conductor coupling the sensor cover to the touch sensor.

According to yet another aspect, there is provided a touch sensor assembly including a touch sensor configured to provide an output in response to contact with a touch area, a sensor cover configured to at least partially cover the touch sensor and including a graphical indicator identifying a position of the touch area, a controller; and a light emitting diode (LED). The LED is configured to illuminate at least a portion of the touch area and to sense an ambient light level adjacent the touch area. The controller is configured to control an illumination level provided by the LED in response to the sensed ambient light level.

According to yet another aspect there is provided a method of monitoring a plurality of touch areas of a touch sensor assembly. The method may include: identifying a first signal of a plurality of signals that exceeds a threshold level for a first time interval, each one of the plurality of signals corresponding to a different one of the plurality of touch areas, the first signal corresponding to a first touch area of the plurality of touch areas; providing a first output signal associated with the first signal; identifying a second signal of the plurality of signals that also exceeds the threshold level for the first time interval, the second signal corresponding to a second touch area of the plurality of touch areas; and changing the first output signal to a second output signal associated with a simultaneous touching of the first touch area and the second touch area if no other of the plurality of signals exceeds the threshold level for the first time interval.

According to yet another aspect there is provided a method of monitoring a plurality of touch areas of a touch sensor assembly. The method may include: identifying a first signal of a plurality of signals that exceeds a threshold level for a first time interval, each one of the plurality of signals corresponding to a different one of the plurality of touch areas, the first signal corresponding to a first touch area of the plurality of touch areas; providing a first output signal associated with the first signal; identifying a second signal of the plurality of signals that also exceeds the threshold level for the first time interval, the second signal corresponding to a second touch area of the plurality of touch areas; and changing the first output signal to a second output signal associated with a simultaneous touching of the first touch area and the second touch area if a reference signal corresponding to a reference electrode does not exceed the threshold level for the first time interval.

According to yet another aspect, there is provided a touch sensor system. The touch sensor system may include a touch sensor configured to provide an output in response to contact with a touch area; a controller coupled to the touch sensor and configured to provide a code representative of the output; and a memory coupled to the controller, the memory configured to receive and store the output in a first time interval and to provide the output in a second time interval wherein the second time interval begins after the first time interval ends.

According to yet another aspect, there is provided a touch sensor system. The touch sensor system may include a touch sensor assembly. The touch sensor assembly may include a first touch sensor configured to provide a first output in response to contact with a first touch area; a second touch sensor configured to provide a second output in response to contact with a second touch area and an anti-swipe touch sensor configured to provide an anti-swipe output in response to contact with an anti-swipe touch area. The touch sensor system may include a controller coupled to the touch sensor assembly wherein the controller is configured to receive the outputs and to provide a code representative of said first output and said second output if the anti-swipe output is not present.

According to yet another aspect there is provided a method of monitoring a plurality of touch areas of a touch sensor assembly. The method may include: identifying a first signal of a plurality of signals that exceeds a threshold level for a first time interval, each one of the plurality of signals corresponding to a different one of the plurality of touch areas, the first signal corresponding to a first touch area of the plurality of touch areas; and determining whether the first touch area corresponds to a first multifunction key. The method may further include identifying a second signal of the plurality of signals that also exceeds the threshold level for at least a portion of the first time interval, the second signal corresponding to a second touch area of the plurality of touch areas; and determining whether the second touch area corresponds to a second multifunction key.

According to yet another aspect there is provided a method of monitoring a plurality of touch areas of a touch sensor assembly. The method may include: identifying a first signal of a plurality of signals that exceeds a threshold level for a first time interval, each one of the plurality of signals corresponding to a different one of the plurality of touch areas, the first signal corresponding to a first touch area of the plurality of touch areas; starting a single key (SK) timer if the first touch area corresponds to a first multifunction key or providing a first output signal associated with the first signal if the first touch area does not correspond to the first multifunction key. The method may further include identifying a second signal of the plurality of signals that also exceeds the threshold level for a portion of the first time interval, the second signal corresponding to a second touch area of the plurality of touch areas; starting a dual key (DK) timer if the second touch area corresponds to a second multifunction key; and providing a second output signal associated with the second signal if the first signal no longer exceeds the threshold and the second touch area does not correspond to the second multifunction key or the SK timer expires.

The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described (or portions thereof), and it is recognized that various modifications are possible within the scope of the claims. Other modifications, variations, and alternatives are also possible. Accordingly, the claims are intended to cover all such equivalents. 

1. A touch sensor system comprising: a touch sensor configured to provide an output in response to contact with a touch area; a controller coupled to said touch sensor and configured to provide a code representative of said output; and a memory coupled to said controller, said memory configured to receive and store said code in a first time interval and to provide said code in a second time interval wherein said second time interval begins after said first time interval ends.
 2. The touch sensor system of claim 1 further comprising a visual indicator wherein said controller is configured to activate said visual indicator in response to said contact with said touch area.
 3. The touch sensor system of claim 1 wherein said memory is a cache.
 4. The touch sensor system of claim 1 wherein said memory is configured to be first in, first out.
 5. The touch sensor system of claim 2 wherein said visual indicator is a light emitting diode (LED).
 6. A touch sensor system comprising: a touch sensor assembly comprising: a first touch sensor configured to provide a first output in response to contact with a first touch area; a second touch sensor configured to provide a second output in response to contact with a second touch area; and an anti-swipe touch sensor configured to provide an anti-swipe output in response to contact with an anti-swipe touch area; and a controller coupled to said touch sensor assembly wherein said controller is configured to receive said outputs and to provide a code representative of said first output and said second output if said anti-swipe output is not present.
 7. The touch sensor assembly of claim 6 further comprising a visual indicator wherein said controller is configured to activate said visual indicator in response to said contact with said first touch area and said second touch area.
 8. The touch sensor system of claim 6 further comprising a memory coupled to said controller, said memory configured to receive and store said code in a first time interval and to provide said code in a second time interval wherein said second time interval begins after said first time interval ends.
 9. A method of monitoring a plurality of touch areas of a touch sensor assembly, said method comprising: identifying a first signal of a plurality of signals that exceeds a threshold level for a first time interval, each one of said plurality of signals corresponding to a different one of said plurality of touch areas, said first signal corresponding to a first touch area of said plurality of touch areas; and determining whether said first touch area corresponds to a first multifunction key.
 10. The method of claim 9, further comprising: identifying a second signal of said plurality of signals that also exceeds said threshold level for at least a portion of said first time interval, said second signal corresponding to a second touch area of said plurality of touch areas; and determining whether said second touch area corresponds to a second multifunction key.
 11. The method of claim 9 further comprising providing a code representative of said first signal based on a result of said determination.
 12. The method of claim 9 further comprising starting a single key timer based on a result of said determination.
 13. The method of claim 12 further comprising providing a code representative of said first signal when said single key timer expires or when said first signal no longer exceeds said threshold level.
 14. The method of claim 10 further comprising providing a code based on a result of said determinations.
 15. The method of claim 10 further comprising starting a dual key timer based on a result of said determinations.
 16. The method of claim 15 further comprising providing a code representative of said first signal and said second signal when said dual key timer expires.
 17. The method of claim 15 further comprising identifying an anti-swipe signal that exceeds a threshold level, said anti-swipe signal corresponding to an anti-swipe touch area wherein said anti-swipe signal is configured to prevent providing a code when said dual key timer expires.
 18. The method of claim 11 further comprising providing said code to memory wherein said memory is configured to receive and store said code and to provide said code for an interval wherein said interval corresponds to an output hold time.
 19. The method of claim 14 further comprising providing said code to memory wherein said memory is configured to receive and store said code and to provide said code at an interval wherein said interval corresponds to an output hold time.
 20. A method of monitoring a plurality of touch areas of a touch sensor assembly, said method comprising: identifying a first signal of a plurality of signals that exceeds a threshold level for a first time interval, each one of said plurality of signals corresponding to a different one of said plurality of touch areas, said first signal corresponding to a first touch area of said plurality of touch areas; starting a single key (SK) timer if said first touch area corresponds to a first multifunction key or providing a first code representative of said first signal if said first touch area does not correspond to said first multifunction key; identifying a second signal of said plurality of signals that also exceeds said threshold level for a portion of said first time interval, said second signal corresponding to a second touch area of said plurality of touch areas; starting a dual key (DK) timer if said second touch area corresponds to a second multifunction key; and providing a second code representative of said second signal if said first signal no longer exceeds said threshold and said second touch area does not correspond to said second multifunction key or said SK timer expires. 